Inheritance, Variation And Evolution(B)(p1/2)

Question 1

What Is DNA?

Answer 1

Deoxyribonucleic acid. It is a polymer and has a double helix structure

Question 2

What are chromosomes ?

Answer 2

Tight coils that contain DNA. Each human cell has 46 chromosomes (2 of 23 human pairs)

Question 3

What are the 23rd pairs referred to?

Answer 3

Sex chromosomes

Question 4

What is a man and women chromosomes?

Answer 4

Male: xy
Female: xx

Question 5

Why are chromosomes drawn within a circle?

Answer 5

Due to This being before cell division (mitosis, meiosis)

Question 6

What are genes?

Answer 6

Small sections of DNA that codes for a protien.

(It codes sequences of amino acid. That can be combined to form many proteins) such a RDB from hemoglobin

Question 7

What are genomes?

Answer 7

Entire sets of genetic material in an organism.
-they are usually inherited from our parents

Question 8

How can someone’s genome help with medical treatment?(3)

Answer 8

They can use genomes to identify inherited diseases.
Or identify the increased risk of getting one

(Help identify migration of ancestors??!)

Question 9

What is an allele?

Answer 9

Different versions of a gene

Question 10

What is the difference between a homozygous and a heterozygous?

Answer 10

Homozygous has the same allele
Whilst heterozygous has 2 different alleles

Question 11

What happens when there’s on dominant and recessive allele?

Answer 11

The dominant allele is exprés

Question 12

What happens when there’s 2 recessive alleles

Answer 12

Recessive allele is expressed

Question 13

What are genotypes?

Answer 13

Collection of alleles we have?

Question 14

What are phenotypes?

Answer 14

Characteristics you get from genotype

Question 15

What is sexual reproduction

Answer 15

Fusion of male and female gametes via fertilization. Which are genetically different to parent

Question 16

What are gamete’s?

Answer 16

They have half genetic material of normal human cell. Considers haploid cells

(Sperm, egg, pollen)

Question 17

What is asexual reproduction?

Answer 17

When there is no mixing of genetic material to produce genetically identical offsprings

Eukaryotic (animal plant) via mitosis

Prokaryotic (bacteria) via binary fusion

Question 18

what is meiosis?

Answer 18

-replicates DNA to make all x
-lines up in centre cell
-chromosomes pull apart(randomly distributed)
-2 arms pulled apart to opposite sides of cell
0divides further mad=ke 4 genetically identical cells called gametes

Question 19

what is variation?

Answer 19

where different individuals have different phenotypes (characteristics) different proteins which are affected by genes and environment

Question 20

what are mutations?

Answer 20

change DNA code-dont affect proteins-so don’t change phenotype(bat can, usually is very bad cases, but sometimes good)

Question 21

what is natural selection?

Answer 21

fittest individuals are select to survive

Question 22

what is evolution?

Answer 22

natural selection of genetic changes that rise to phenotypes best suited for environment/

inherited characteristics in population over multiple generations, could lead to change whole species

[shown in antibiotic resistance and fossils]

Question 23

what fossil evidence can be used for evolution?

Answer 23

• gradual replacement minerals
  -rock like substance
  -casts(clay is left with gap, that was same size as organism)
  -preservation: no decay, so completely stays intact

Question 24

what is classification system?

Answer 24

domain-kingdom-phylum-class-order-family-genus-species

Question 25

what are 3 domains?

Answer 25

archaea, bacteria, eukayrota