KS Learning
GCSE Biology

GCSE Biology Flash Card Questions

KS Learning can provide extra lessons for maths from gcse maths tutors in London and help with gcse maths past papers, gcse maths revision notes, and gcse maths revision worksheets. Maths private tuition at its tuition centre can improve maths knowledge and performance through maths lessons, mathematics tutorials and maths tuition Twickenham.

B13 Reproduction

B13.1 Types of reproduction

Question	Answer
When is genetic information passed from parents to their offspring?	during reproduction through chromosomes passed from parents to offspring
Name the 2 types of reproduction.	• sexual reproduction • asexual reproduction
How many parents are involved in asexual reproduction?	just one parent
How do cells reproduce in asexual reproduction?	only mitosis
Compared to sexual reproduction, what does not happen in asexual reproduction?	there is no fusing of gametes (special sex cells) and thus no mixing of genetic information
How do parents and offspring compare genetically after asexual reproduction?	parents and offspring are genetically identical
What is yeast?	single celled fungi
How does yeast reproduce?	they reproduce asexually producing a mass of cells by mitosis
Where is asexual reproduction common?	small plants, small animals, bacteria, and fungi
What is a genetically identical offspring called?	a clone
Name three larger plants that reproduce asexually.	• daffodils • brambles • strawberries
How many parents are involved in sexual reproduction?	sexual reproduction involves two parents
What happens in sexual reprodution at a cell level?	a male sex cell and a female sex cell fuse to form a a zygote that develops into a new individual
What is the proper term for a sex cell?	a gamete
What is the male gamete called in animals?	sperm
What is the male gamete called in plants?	pollen
What is the female gamete called in animals?	ovum or egg cell
What is the female gamete called in plants?	ovum or egg cell
What type of cell division is used to produce gametes?	meiosis
How do cells produced by meiosis compare with those by mitosis?	• mitosis produces identical cells while cells from meiosis vary • cells produced by meiosis have half the number of chromosomes to those produced by mitosis • meiosis is used to produce cells for reproduction only and mitosis is used to produce all other cells
What is the new cell called when two sex cells fuse?	a zygote
Why must the number of chromosomes be halved before reproduction can occur?	so when gametes fuse together the new cell has the correct number of chromosomes
How is variation achieved in sexual reproduction?	• offspring inherit genetic information from both parents • they therefore have some characteristics from each parent • but are not identical to either - so there is variation
What is the disadvantage of sexual reproduction?	it depends on two sex cells from different individuals meeting and fusing which requires significant resources
What is the advantage of sexual reproduction?	it introduces variation in offspring which is an advantage for the long-term survival of the species
How many chromosomes in a human gamete?	23 chromosomes
How many chromosomes in a human zygote?	46 chromosomes
How many chromosomes in human cells other than gametes?	46 chromosomes
What is asexual reproduction?	one parent producing offspring with identical genes and characterisitcs
What is sexual reproduction?	two parents producing offspring with a mixture of genes and characterisitcs from the two parents

B13 Reproduction

B13.2 Cell division in sexual reproduction

Question	Answer
Name the types of cell division.	• mitosis • meiosis
Where does mitosis take place?	in tissues all over the body and during asexual reproduction
Where does meiosis take place?	in the reproductive organs only
What are the reproductive organs called in humans?	the ovaries and the testes
What does meiosis produce?	sex cells, called gametes, with half the number of chromosomes to the original cell
Where are female gametes produced in animals?	the ovaries
Where are male gametes produced in animals?	the testes
What does meiosis do to the chromosome number?	it halves the number of chromosomes in each cell
Where do the chromosomes in a body cell come from?	there are two sets, one from the mother and the other from the father
What happens to the chromosomes in meiosis?	• the chromosomes double so there are 4 sets instead of the regular 2 sets • each chromosome forms a pair of chromatids • the cell divides twice in quick succession • four gametes are formed each with a single set of chromosomes
Are the gametes produced by meiosis identical?	no, they are all different
How is variation introduction through the gametes?	the gametes contain a random mixture of the original chromosomes
How many sperm do the testes produce?	around 400 million sperm every 24 hours
What distance must the sperm travel compared to its length?	100 000 its own length
What is the chance of a sperm reaching an egg?	less than 1 in 1 million
What is the term for a cell with one set of chromosomes?	haploid
Name a cell that is haploid.	a gamete, both sperm and ovum
What is the term for a cell with two sets of chromosomes?	diploid
Name a cell that is diploid.	all body cells are diploid eg muscle cell, skin cell
What process produces haploid cells?	meiosis
What process produces diploid cells?	mitosis
What is fertilisation?	a male and female gamete (haploid) fuse to form a new diploid body cell
What is the consequence of variation for the newly fertilised egg?	the combination of genes in each newly fertilised egg is unique
What happens to the new body cell after fertilisation?	• the new body cell begins to reproduce by mitosis • the number of cells increases rapidly • the cells begin to differentiate to form tissues, organs and organ systems • eventually, a new individual forms
What are the offspring produced in asexual reproduction?	clones
Why does asexual reproduction produce clones?	the cells that form the new offspring are formed by mitosis, which produces genetically identical cells - there is no variation in the genetic material
How is variation introduced in sexual reproduction?	• each gamete is different introducing variation • when the gametes fuse, one of each gene comes from each parent, introducing yet more variation
What is an allele?	different versions of the same gene

B13 Reproduction

B13.3 The best of both worlds (single science only)

Question	Answer
What are the advantages of asexual reproduction?	• it is time and energy efficient as neither is required to find a partner or spread gametes • it is usually faster than sexual reproduction • it produces large numbers of offspring quickly
What are the disadvantages of asexual reproduction?	if one organism cannot survive because of unfavourable conditions, all organisms are threatened
State an example of how asexual reproduction be used by humans.	asexual reproduction can be speeded up for food production
What are the disadvantages of sexual reproduction?	• it takes time and energy to find at least two parents or two gametes • it is usually slower than asexual reproduction
What is the advantage of sexual reproduction?	it produces variation in the offspring
What is the benefit of variation?	if the environment changes, the organism has a survival advantage as some offspring may be able to survive and reproduce
What is natural selection?	when conditions change, the individuals best suited to the change will survive and breed passing on the characteristics that give them the advantage
How do humans exploit natural selection?	humans speed up natural selection in selective breeding to for example produce more food
How do fungi reproduce?	sexually and asexually
What is the most common type of reproduction in fungi?	asexual reproduction
What do fungi use to reproduce asexually?	spores
What are toadstools and puffballs?	they are asexual fruiting bodies full of spores
How are spores produced?	by mitosis
How do spores compare genetically to the parent plants?	they are genetically identical
How are new fungi formed?	spores germinate to form new fungi
How many sets of chromosomes are in a fungal cell?	one set of chromosomes (n)
How many sets of chromosomes are in a spore?	one set of chromosomes (n)
What are hyphae?	thin threads that combine to form the visible structures
When do fungi reproduce sexually?	when conditions are not good, for example, when it is dry
How do fungi reproduce sexually?	• two hyphae from different fungi join to form a single hypha • the nuclei fuse to form a nucleus with two sets of chromosomes (2n) • meiosis takes place to produce spores each with a single set of chromosomes (n) • the new spores are genetically different to the parents • some of the new spores may be better adapted to survive the adverse conditions
How do plants reproduce?	many plants reproduce by sexual and asexual reproduction
How are seed produced?	by sexual reproduction
Where are the sexual organs of plants?	the the flower
What are male gametes called in plants?	pollen
What is the plant equivalent of mating?	pollination
What must happen for pollination to happen?	pollen from one plant must reach the female organs of another plant
How are gametes produced in plants?	meiosis
What is the role of the flower in pollination?	• to attract animal pollinators like insects, bats, or birds • to make it easy for wind to carry pollen to another flower
What happens in pollination?	pollen fuses with the egg cell forming a seed
What is the benefit of sexual reproduction for plants?	it introduces variation and through natural selection, enables plants to survive as conditions change
How do plants reproduce?	many plants reproduce by sexual and asexual reproduction
Give two examples of asexual reproduction in plants.	• new plants growing on specialised stems called runners such as strawberries • the division of bulbs in plants such as daffodils
Name of benefit of both sexual and asexual reproduction to plants like daffodils.	new plants are formed evein if flowers are destroyed by say frost or eating, or fail to pollinate
What is the main disadvantage of asexual reproduction to plants?	plants are genetically identical to their parents so there is no variation
How is malarie transmitted to humans?	by mosquitoes
How does the malarial parasite reproduce?	they reproduce differently at different stages using both sexual and asexual reproduction
Where does the malarial parasite live for its life cycle?	part of the life cycle is spent in the body of the female mosquito and part of the life cycle is spent in the blood and organs of human beings
How does the malarial parasite reproduce in humans?	asexually in human liver and blood cells
How does the malarial parasite reproduce in mosquitoes?	• the mosquito takes her blood meal • the temperature of the mosquito is lower than the temperature of a human • the drop in temperature triggers sexual reproduction in some of the blood cells • the sexual forms break out of the blood cells • the sexual forms fuse to form a zygote with two sets of chromosomes • the zygote undergoes meiosis to produce asexual parasites • the new asexual parasites are ready to infect humans • the parasites show a lot of variation

B13 Reproduction

B13.4 DNA and the genome

Question	Answer
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	• x • x • x • x • x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	• x • x • x • x • x

B13 Reproduction

B13.5 DNA structure and protein synthesis (single science only)

Question	Answer
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	• x • x • x • x • x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	• x • x • x • x • x

B13 Reproduction

B13.6 Gene expression and mutation (single science only)

Question	Answer
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	• x • x • x • x • x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	• x • x • x • x • x

B13 Reproduction

B13.7 Inheritance in action

Question	Answer
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	• x • x • x • x • x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	• x • x • x • x • x

B13 Reproduction

B13.8 More about genetics

Question	Answer
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	• x • x • x • x • x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	• x • x • x • x • x

B13 Reproduction

B13.9 Inherited disorders

Question	Answer
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	• x • x • x • x • x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	• x • x • x • x • x

B13 Reproduction

B13.10 Screening for genetic disorders

Question	Answer
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	• x • x • x • x • x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	x
x	• x • x • x • x • x