YR 9 - Genetics and Inheritance

Question 1

what are chromosomes?

Answer 1

chromosomes are structures found in the cell’s nucleus that’s made of DNA.

Question 2

what does DNA stand for?

Answer 2

DeoxyriboNucleic Acid

Question 3

what is DNA?

Answer 3

DNA is a chemical code that contains instructions called genes.

Question 4

what is a gene?

Answer 4

a gene is a section of DNA that carries the code for a particular protein.

Question 5

what are alleles?

Answer 5

alleles are different forms of the same gene.

Question 6

what are dominant alleles?

Answer 6

the dominant allele is the allele of a characteristic that is always expressed in an organism.

Question 7

what are recessive alleles?

Answer 7

the recessive allele is the allele whose characteristics is only expressed in if the allele is inheritanced from both your parents

Question 8

what is genetic variation?

Answer 8

genetic variation is the inheritance of different combinations of genes & alleles that controls the development of different characteristics.

(the difference in DNA among individuals)

Question 9

what are phenotypes?

Answer 9

the phenotype is the physical appearance of characteristics e.g. dimples or no dimples

Question 10

what are genotypes?

Answer 10

genotype is the genetic make-up of an individual.

Question 11

how can a person be heterozygous?

Answer 11

a person is heterozygous for a trait if they have two different alleles.

Question 12

how can a person be homozygous?

Answer 12

a person is homozygous for a trait if they have two of the same alleles.

Question 13

what is monohybrid inheritance?

Answer 13

monohybrid inheritance is the inheritance of a single characteristic controlled by a pair of allele.

Question 14

what is fertilisation?

Answer 14

fertilisation is the fusion of male and female gamete (sperm and egg cell)

Question 15

what is a zygote?

Answer 15

a zygote is the fertilised egg.

Question 16

what happens in natural selection?

Answer 16

in natural selection, individuals in a species show a wide range of variation due to differences in the gene.

Question 17

what is natural selection?

Answer 17

natural selection is when individuals with characteristics most suited to their environment are more likely to reproduce and survive.
— the genes that allowed them to be successful are then passed on to their offspring.

Question 18

what is variation?

Answer 18

variation is all the differences which exists between members of the same species.

Question 19

how can variation be caused?

Answer 19

variation can be caused by the environment, genetics or by both.

Question 20

what are the types of variations?

Answer 20

the two types of variation are continuous and discontinuous.

Question 21

what is discontinuous (discrete) data?

Answer 21

discontinuous data is presented as a finite number that can be counted - the units of measure cannot be split.

Question 22

what is continuous data?

Answer 22

continuous data is presented as an infinite amount of possible values that can be measured - there is a scale of measurement.

Question 23

what are some examples of discontinuous (discrete) data?

Answer 23

• shoe sizes
• result of rolling a die
• number of orients in a hospital
• population of a country
• number of books checked out of a library

Question 24

what are examples of continuous data?

Answer 24

• weight
• height
• length
• time
• temperature

Question 25

what is competition?

Answer 25

competition is when **animals and plants have to compete for limited resources**. • the **best adapted animals or plants will win and survive**.

Question 26

what do plants compete for?

Answer 26

plants compete for: • **water** • **light** • **space** • **minerals from the soil**

Question 27

what do animals compete for?

Answer 27

animals compete for: • **territory** • **mates** • **food** • **shelter**

Question 28

what is adaptation?

Answer 28

adaptation is **the features or characteristics of an animal or plant that allow it to live successfully in its habitat**.

Question 29

what causes adaptations?

Answer 29

adaptations are caused by **changes to the environment surrounding an organism over time to aid survival**.

Question 30

# Define: Physical adaptations

Answer 30

A physical adaptations is **a changing feature of a living thing that helps it to survive in a particular environment** • usually **happens very gradually over generations (years)** ##Footnote e.g., different patterns or colours

Question 31

# Define: Behavioural adaptations

Answer 31

A behavioural adaptation is **a thing that an organism does to survive in a particular environment** ##Footnote e.g., the way they feed, breed or move

Question 32

# Define: Extinction

Answer 32

extinction is when **there are no more living members of an individual species**.

Question 33

# Define: Critically endangered

Answer 33

critically endangered is when **there is an extremely high risk of extinction in the wild**.