Aim: How do our cells
develop, grow and repair?
 Do
Now: Explain
..is reproduction
necessary to
maintain
homeostasis in an
organism?
 Homework:
Review book-topic 4
Explain…Is reproduction necessary for
an organism to maintain homeostasis?
Reproduction is needed to pass on
hereditary information for the
continuation of an organism
BUT….
it is NOT needed to maintain
homeostasis!
Reproduction
A characteristic of all living
things that result in the
continuation of life from one
generation to the next.
Characteristics of
Living Things?

Organisms have a varied lifespan from a
few hours to many years.

Each organism undergoes a lifecycle
from the time of its formation  death

One or two parents
All Organisms are Made up of
Cells.

UNI and Multi Celled organisms MUST
reproduce to grow, develop and heal.
(offspring are IDENTICAL)
This type of reproduction is called
Asexual reproduction AKA Mitosis

Species Survival

Multi-celled organisms MUST reproduce to
pass on hereditary information.
Offspring are UNIQUE)

This type of reproduction is called
Sexual reproduction
Aim: How do our cells
develop, grow and repair?
 Do
Now: Explain
..is reproduction
necessary to
maintain
homeostasis in an
organism?
 Homework:
What is cell division?

A cell that has undergone growth and is
ready to divide is called a MOTHER CELL
The division of a mother cell
gives us 2 equal
daughter cells

Mitosis

Is the duplication and distribution of
nuclear material. (chromosomes/DNA)

Each daughter cell receives chromosomes
identical in composition to the
chromosomes of the
mother cell.
What is the Purpose of Mitosis?
Purpose
of Mitosis
GROWTH
DEVELOPMENT
REPAIR
All living things have DNA that coil
into Chromosomes
Each Species is Different in the
Number of Chromosomes

Humans have


Dogs have


46 chromosomes
38 chromosomes
Fruit Flies have

8 chromosomes
But the way in which the chromosomes
get distributes when they divide is the
same in all organism
Mitosis
in Humans
46
46
46
But the way in which the chromosomes
get distributes when they divide is the
same in all organism
Mitosis
in Dogs
38
38
38
But the way in which the chromosomes
get distributes when they divide is the
same in all organism
Mitosis
in Fruit Flies
8
8
8
What is Mitosis?

Is the duplication and
distribution of
nuclear material.
(chromosomes/DNA)
Each daughter cell
receives the same
number of
chromosomes as the
mother cell.

Summary

Which row in the
chart below best
describes asexual
reproduction?
Row
Number of
Parents
Comparison of
Offspring to
Parents
one
identical
one
different
two
identical
two
different
1.
2.
3.
4.
Asexual reproduction of organisms
normally results in new organisms
that contain cells with
1.
2.
3.
4.
more chromosomes than are found in the
cells of the parent
half the number of chromosomes
the same number of chromosomes
fewer chromosomes that are found in the
cells of the parent
Which phrase best describes the
process represented in the
diagram?
1.
2.
3.
4.
germination of a pollen grain in a flower
identical gametes being formed by
mitotic cell division
development of seeds in a ovule
daughter cells being formed by mitotic
cell division