BIO 165: Life Cycles and Cell division

Define Growth

an increase in an organism's size, generally via cell division

Define Development

changes that occur as an organism matures, including growth, cell specialization, and other processes

What do all life cycles have in common

birth, growth, reproduction, death

Diagram the human life cycle

1) zygote > 2) mitosis > 3) Meiosis (sperm and eggs) > 4) fertilization

What is a gamete

sex cell > sperm and eggs

What is a zygote

fertilized egg (the combination of fusing of sperm and eggs)

Define fertilization

joining of sperm and egg

What are somatic cells?

any cell of a living organism other than the reproductive cells

All cells are produced by...

division of other cells

what are germ cells

(gametes) for sexual reproduction

What is the function of mitosis?

growth and repair make more somatic cells

What is the function of meiosis

makes germ cells for sexual reproduction (haploid)

What is a chromosome made of

Tightly coiled DNA and several types of protein (Histones)

How many DNA molecules are there in a chromosome

2

How does the number of chromosomes vary among different organisms

worm- 4, dogs- 76, human 46 (but all even numbers)

how many chromosomes do humans have

46

What are sister chromatids, and how do they compare to each other

genetically identical DNA molecules

What are homologous chromosome pairs?

1) The same size and structure

2) contain the same genes in the same order

3) In each pair, one chromosome comes from the sperm and one from the egg.

4) NOT IDENTICAL (ONE FROM MOM AND DAD)

5) The nucleotide sequence is not the same

6) They may have different forms of the same gene(different alleles)

What is a diploid cell? What types of cells are diploid

A cell that contains two complete sets of chromosomes, with one set inherited from each biological parent

-This is 46 chromosomes, consisting of 22homologous pairs plus our sex chromosomes

What is a haploid cell?

Our gametes contain only of the chromosome number - this is called haploid (n)

How many chromosomes do human diploid cells have

46

What is the function of mitosis

Make somatic cells for growth and repair (cloning of cells)

What is the key function of meiosis

make gametes (sex cells)

What are the key differences between mitosis and meiosis that result in very different cells being produced?

Mitosis:

: Sister chromatids separate during anaphase

2 daughter cells are produced

Diploid (46)

Daughter cells are identical to the parent cell

Made for growth and repair

Meiosis:

Homologous partners separate during Anaphase

4 daughter cells are produced

Haploid 23

Not identical to parents

Makes gametes for reproduction

How are the two daughter cells produced via mitosis and meiosis different

Mitosis (2) identical

Meiosis (4) different

How do the daughter cells produced by meiosis compare to the parent cells

different (haploid)