DNA and Chromosomes · What is the role of chromosomes? Chromosomes carry the genetic information...

DNA and Chromosomes

Prokaryote (vs) Eukaryote

Similarities between Prokaryotes and Eukaryotes

Prokaryotes and Eukaryotes both contain:

DNA

Ribosomes

Cell membrane (aka Plasma membrane)

Cytoplasm

Differences between Prokaryotes and Eukaryotes

Prokaryotes:

No nucleus

DNA is circular in the cytoplasm

No membrane bound organelles

Eukaryotes:

DNA inside nucleus

Contain membrane bound organelles

ReproductionReproduction is the process by which an organism produces others of the same kind.

Asexual ReproductionNew organisms are

made from only one parent.

The new organism is identical to the parent.

Types of Asexual ReproductionBinary Fission

Done by bacteria

Types of Asexual ReproductionBudding

Done by Bacteria, fungi, jellyfish and sea anemones

Types of Asexual Reproduction

Regeneration Done by some reptiles and amphibians

Types of Asexual Reproduction

Mitosis Done by all eukaryotic organisms

Binary Fission❑ The cell grows to a certain size

❑ Begin to replicate, their DNA once they have grown to a certain size.

❑ When DNA replication is complete,the cells divide through a processknown as binary fission.

❑ Binary fission is a form of asexual reproduction during which two genetically identical cells are produced.

Budding

Small outgrowth called a bud forms from the parent cell.

DNA is replicated

This bud continues to increase in size and becomes and independent organism from the parent

Regeneration

Process by which some organisms replace or restore lost body parts.

Sexual ReproductionRequires a sperm cell and an egg cell.

Requires two organisms.

FertilizationWhen a sperm joins with an egg, and a zygote forms.

Zygote- Made of one cell that forms a new organism.

Which of the following is incorrect

regarding prokaryotes?

A. Have a nucleus

B. Do not contain organelles

C. Do have a cell wall

D. Do contain DNA

How are sexual reproduction and asexual reproduction different from each other?

A. sexual reproduction requires two parents and asexual reproduction requires only one parent

B. asexual reproduction requires two parents and sexual reproduction requires only one parent

C. mutation rates are lower in sexual reproduction than in asexual reproduction

D. asexual reproduction occurs only in multicellular organisms.

7. Which type of reproduction leads to

increased genetic variation on a

population?

A. Budding

B. Asexual reproduction

C. Sexual reproduction

D. Mitosis

Eukaryotes Prokaryotes

Nucleus No Organelles

Ribosomes Cell Membrane

DNA No Nucleus

Organelles

Bacteria

Animals, Plants, Fungi and Protists

Cytoplasm

DNA:(Deoxyribonucleic Acid)

Chromosomes are made out of DNA.DNA looks like a double-helix, or a twisted ladder.DNA codes for the creation of proteins.

Structure of DNADNA is made up of

repeating series of nucleotides.

A nucleotide consists of:Sugar GroupPhosphate GroupNitrogen Base

Chromosome Structures

What is the role of chromosomes?

❑ Chromosomes carrythe genetic information that is passed on from one generation of cells tothe next.

❑ Every cell must copyits genetic information before cell division begins.

❑ Chromosomes make it possible to separate DNA precisely during cell division.

MITOSIS

Mitosis produces ONLY body cells.They are all identical to

each other.(AKA somatic cells!!)

All body cells contain 46 chromosomes

How do little elephants grow up to be BIG

elephants?

Why do our cuts heal?

Cell Division—Mitosis

Cell Division —process by which a cell divides into2 IDENTICAL daughter cells

• Why do cells need to divide?

1. Growth

2. Repair of damaged tissue

3.Replacement

2

Daughter

Cells

Understanding the Basics

• The original cell is called the parent cell

• 2 new cells are called daughter cells

• Each daughter cell is exactly like the parent cell • Same number of chromosomes

Parent cell

Cell cycle

Mitosis: Forming Body Cells

Meiosis

Meiosis produces ONLY sperm and egg cells. (AKA gametes)

All sex cells contain 23 chromosomes(AKA gametes!!)

Homologous Chromosomes Code for the same gene in the

same region of the chromosome, but they are not the same. One is from mom and one from dad.

Sperm

23 Chromosomes

Egg

23 Chromosomes

Baby

46 Chromosomes

Meiosis: Forming Sex Cells

Each chromosome consists of 2 _____.

a. centrofibers

b. chromatids

c. daughter cells

d. centrioles

What structures that carry DNA called?

A) cyclins

B) chromatids

C) chromosomes

D) kinases

Which of the following forms sex cells?

A) mitosis

B) asexual reproduction

C) regeneration

D) meiosis

How many chromosomes do body cells

contain?

A) 23

B) 46

C) 96

D) 24