Genetics

Question 1

Name 2 types of variations of genes

Answer 1

Environmental
Genetic

Question 2

Different components of animal cell

Answer 2

Nucleus controls the cell and contains DNA/ Chromosomes
Cytoplasm - chemical reactions
Cell membrane - allows things to leave/enters
Mitochondria - respiration

Question 3

What is the structure of DNA

Answer 3

DNA is double stranded, double helix molecule.
Found in the nucleus
Provides our genetic code
It is made up of chromosomes

Question 4

How many pairs of chromosomes?

Answer 4

23 pairs (46 chromosomes)

Question 5

How many chromosomes are in sex cell ?

Answer 5

23 chromosomes

Question 6

Generic name for sex cells
unfertilised egg cell
fertilised egg cell?

Answer 6

Gamete
Ovum
Zygote

Question 7

How is a genetic disorder inherited?

Answer 7

You receive half your genes from each biological parent and may inherit a gene mutation from one parent or both.

Question 8

What is a gene?

Answer 8

Coding part of chromosome e.g. eye colour

Question 9

What is an allele?

Answer 9

Alternate form of a gene

Pairs of genes for a characteristic

e.g. a gene is eye colour and the alleles are either blue or brown

Question 10

what is it called when a person has two identical alleles ?

Answer 10

homozygous alleles e.g. TT

Question 11

what is it called when a person has two different alleles ?

Answer 11

heterozygous alleles e.g. Tt

Question 12

what describes the alleles of an individual ?

Answer 12

genotype e.g .TT

Question 13

what describes the physical appearance of a person ?

Answer 13

phenotype e.g blue eyes

Question 14

What is a genetic cross?

Answer 14

genotypes and phenotypes inherited in a given genetic cross e.g. punnett square will work out the cross between 2 people

Question 15

Name 2 advantages of cross-breeding

Answer 15

desired characteristic
avoid genetic defects
aesthetic reasons
Economic
Eliminate Disease
New varieties
Change evolution of a species
Fitter/stronger animals

Question 16

Name 2 disadvantages of inbreeding

Answer 16

susceptible to diseases
weaker animals
genetic defects

Question 17

What is the cross-breeding process?

Answer 17

Select parents with desired characteristics to produce offspring
Offspring with desired characteristics are also selected and bred
This is repeated

The more you cross-breed the less genes characteristics

Question 18

What is selective breeding?

Answer 18

2 humans choose parents to breed together
for desirable characteristics so that children will also have desirable characteristics

Question 19

What are the stages of selective breeding?

Answer 19

1. Choose parents to breed
2. Breed these parents.
3. Choose the best offspring, to produce the next generation.
4. Repeat the process continuously over many generations, until all offspring show the desired characteristics.

Question 20

What is genetic engineering?

Answer 20

Process which changes the gene of an organism by introducing a gene from another organism for desired characteristic.

Question 21

What does GMO stand for?

Answer 21

Genetically Modified Organisms

Question 22

Advantages and disadvantages of genetically engineering organisms?

Answer 22

Advantages:
Cure for genetic disease e.g. insulin
Produce new foods
Getting rid of illness
More nutrients
Less pesticides
Improve diet
Resistant to disease
Produce greater yield

Disadvantages:
Expensive so available to select group
Unknown impact of GMO crops e.g. allergies
Harmful changes to animals

Question 23

What are the male and female genotypes?

Answer 23

XX and XY

Question 24

What is a gamete?

Answer 24

Sex cell

Question 25

What process MODIFIES genes in an organism?

Answer 25

Genetic engineering

Question 26

What process produces organisms with identical genes e.g insulin?

Answer 26

Cloning

Question 27

What is a clone

Answer 27

Making a genetically identical copy o fan individual (naturally e.g. twins or articificially)

Question 28

Process for cloning

Answer 28

1. Remove nucleus from unfertilised egg cell 2. Remove nucleus from an adult body cell, such as a skin cell, is inserted into the egg cell 3. Electric shock stimulates the egg cell to divide to form an embryo 4. Embryo develops into a ball of cells, it is inserted into the womb of an adult female to continue its development

Question 29

Process for Genetic Engineering

Answer 29

1. Select desired characteristic. 2. Cut gene out of chromosome 3. Transfer gene into another organism. 4. Produce new characteristic Gene (from Human) + Bacteria DNA = Mass produce bacteria new characteristic

Question 30

What causes a cell to be genetically identical

Answer 30

The cell copies - or 'replicates' - its chromosomes, and then splits the copied chromosomes equally

Question 31

What is cell division called?

Answer 31

Mitosis (Meiosis is specifically sex cells)

Question 32

What happens before a cell divides/mitosis?

Answer 32

Chromosomes are copied.

Question 33

Why does sexual reproduction produce a new variety of onion?

Answer 33

Genetic variation - producing offspring that are genetically unique, combining genes from two parents in new ways. This genetic variation is crucial for the production of new onion varieties with potentially desirable traits, such as improved taste, resistance to diseases, or better storage capabilities

Question 34

How do mitochondria help sperm cells carry out their function?

Answer 34

Produce energy for the movement of the sperm.

Question 35

Why is nucleus in sperm cell different to other body cells

Answer 35

Sperm cells only contain one set of chromosomes (23 !)

Question 36

Why stem cell used to treat some diseases?

Answer 36

Replace cells that are damaged Stem cells can divide to produce new cells, which can then divide into different cell types. They therefore have the potential to be transplanted into patients to treat disease.

Question 37

What is sexual reproduction?

Answer 37

Gamete (sperm cell) combines with another gamete (egg cell) to produce a zygote (fertilised egg cell)