bio 13.1-13.5

Question 1

What is sexual reproduction?

Answer 1

where genetic info from two organisms, a father and a mother is combined to produce offspring which are genetically different to either parent.

Question 2

how many chromosomes does a gamete have?

Answer 2

23 (half the amount of normal human cells)

Question 3

what happens in fertilization?

Answer 3

The egg from the mother and sperm from the father fuse together to from a cell with the full number of chromosomes.(half from each parent)

Question 4

what does the offspring of sexual reproduction contain?

Answer 4

a mixture of their parents genes and inherited features

Question 5

what does the mixture of genetic material produce?

Answer 5

variation

Question 6

what are the gametes of flowering plants?

Answer 6

egg cells and instead of sperm they have pollen

Question 7

what is asexual reproduction?

Answer 7

When there’s only one parent so the offspring are genetically identical to the parent.

Question 8

What process do mothers and fathers use to produce gametes?

Answer 8

meiosis

Question 9

what process does asexual reproduction happen through?

Answer 9

mitosis, an ordinary cell makes a new one by dividing into 2.

Question 10

What does the ordinary cell in asexual reproduction form?

Answer 10

a new cell with exactly the same genetic information as the parent. (a clone)

Question 11

process of meiosis making gametes

Answer 11

-copies of the genetic info are made
- cell divides twice to form 4 gametes, each with a single set of chromosomes
-all gametes genetically different from eachother.

Question 12

what happens after two games are fused during fertilization?

Answer 12

-The resulting new cell divides by mitosis.
- mitosis repeats many times to produce so number of cells increases
-As the embryo develops cells differentiate.

Question 13

Advantages of sexual reproduction

Answer 13

Advantages
- produces variation in offspring
- if environment changes, variation gives survival advantage by natural selection.
-Natural selection can be speeded up by humans in selective breeding to increase food production.

Question 14

Advantages of asexual reproduction

Answer 14

Advantages:
- only one parent needed
- more time and energy efficient as do not need to find a mate.
-faster than sexual reproduction
-many identical offspring can be produced when have favorable conditions.

Question 15

what does mitosis form?

Answer 15

Identical cells

Question 16

what does meiosis form?

Answer 16

non-identical cells

Question 17

how are gametes formed?

Answer 17

cells in reproductive organs divide by meiosis

Question 18

What organisms reproduce by both methods?

Answer 18

-Malarial parasites reproduce asexually in human host but sexually in the mosquito.
- Many fungi reproduce asexually by spores but reproduce sexually to give variation.
-Many plants produce seeds sexually, but also reproduce asexually by runners such as strawberry plants, or bulb division such as daffodils.

Question 19

Where is the genetic material in a cell?

Answer 19

-The genetic material in the nucleus of a cell is composed of a chemical called DNA.

Question 20

what is DNA?

Answer 20

A polymer made up of two strands forming a double helix.

Question 21

What structures is the DNA contained in?

Answer 21

chromosomes

Question 22

What is a gene?

Answer 22

A small section of DNA on a chromosome. Each gene codes for a particular sequence of amino acids, to make a specific protein.

Question 23

What is a genome?

Answer 23

the entire genetic material of an organism.(The human genome has been studied and will help with medicine in the future)

Question 24

Why is understanding the human genome important?

Answer 24

• search for genes linked to different types of diseases.
• understanding and treatment of inherited disorders.
• can use in tracing human migration patterns from the past

Question 25

What is DNA made up of?

Answer 25

repeating nucleotide units.

Question 26

What is a nucleotide?

Answer 26

The combination of a sugar, a phosphate and one of four different bases attached to the sugar.

Question 27

What are the 4 bases DNA contains?

Answer 27

(C,G) and (A,T)

Question 28

What does the sequence of 3 bases show?

Answer 28

The code for a particular amino acid, the order of bases controls the order in which amino acids are assembled to from a particular amino acid.

Question 29

what is protein synthesis

Answer 29

making protein

Question 30

what happens in protein synthesis?

Answer 30

Proteins are synthesized(made) on ribosomes. according to a template. Carrier molecules bring specific amino acids to add to the growing protein chain in the correct order.

Question 31

what happens when the protein chain is complete?

Answer 31

It folds up to form a unique shape. This unique shape enables the proteins to do their job as enzymes, hormones or forming structures in the body like collagen.

Question 32

How can a change in the DNA structure may change the protein synthesized by a gene?

Answer 32

A change of order in the DNA bases will alter template made. A different template may result in a different sequence of amino acids joining together. This will form a different protein.