B6 Inheritance, Variation and Evolution

Question 1

What are the male and female gametes in humans? (and flowering plants)

Answer 1

Sperm and egg (pollen and egg).

Question 2

What is the difference between sexual and asexual reproduction?

Answer 2

Sexual ? 2 parents so offspring genetically different. Asexual ? 1 parent so genetically identical offspring (clones).

Question 3

What is meiosis?

Answer 3

Used to make gametes ? 1 cell divides twice. Makes 4 genetically different cells with only half the number of chromosomes.

Question 4

Where in the cell is the genetic material found?

Answer 4

Nucleus

Question 5

What is a gene?

Answer 5

A section of DNA that codes for a particular protein

Question 6

What is a mutation?

Answer 6

A change in a gene (happen all the time ?most have no obvious effect)

Question 7

What is a genome?

Answer 7

All of the genetic material of an organism.

Question 8

Give 3 reasons why it is important to understand the human genome.

Answer 8

Find genes linked to diseases, understand inherited disorders, trace human migration patterns.

Question 9

What is an allele?

Answer 9

Different types of a gene e.g. B ? allele for brown hair b- allele for blond

Question 10

What do heterozygous and homozygous mean?

Answer 10

Heterozygous ? has 2 different alleles for a gene e.g. Bb Homozygous ? has 2 identical alleles for a gene e.g. BB or bb

Question 11

What is the difference between genotype and phenotype?

Answer 11

Genotype ? the genes you have e.g. Bb. Phenotype ? what you look like e.g. brown hair

Question 12

What are the genotypes for male and female?

Answer 12

Male = XY Female = XX

Question 13

What is natural selection?

Answer 13

1. There is wide variation in all species. 2. The ones best adapted to their environment will survive and reproduce. 3. Their genes (which made them best adapted) are passed on.

Question 14

What is evolution?

Answer 14

Gradual changing of an organism over time due to natural selection.

Question 15

What evidence do we have for evolution?

Answer 15

Fossils and antibiotic resistance in bacteria.

Question 16

What is selective breeding?

Answer 16

When humans select parents to breed to produce offspring with desired characteristics.

Question 17

What is genetic engineering?

Answer 17

When genes are inserted into an organisms genome to give a desired characteristic.

Question 18

What are GM crops?

Answer 18

They have been genetically engineered e.g. so insects stop eating them.

Question 19

Give 3 ways that fossils can be formed.

Answer 19

1. Parts of organism doesn?t decay 2. Parts of an organism are replaced by minerals as they decay 3. Traces of animals or plants like footprints and burrows are preserved.

Question 20

Give 3 ways extinction could happen.

Answer 20

E.g. change of environment, lack of food, new predator, new diseases.

Question 21

How does antibiotic resistance happen?

Answer 21

Mutations cause some bacteria to not be killed by antibiotics (resistant). They survive and reproduce and therefore spread.

Question 22

How can we prevent antibiotic resistance?

Answer 22

Don?t take antibiotics for viral illnesses. Take the whole course of tablets.

Question 23

What are the 3 domains that organisms can be classified into?

Answer 23

Archaea (v primitive), Bacteria, Eukarya (plant and animals etc.)