Name: Poon Wing Ching (Prudence) Tse Man Ki (Annie) Wong Chi Yin (Stanley) By Group 3 (Part One)

Name: Poon Wing Ching (Prudence) Tse Man Ki (Annie)

Wong Chi Yin (Stanley)

By Group 3By Group 3

(Part One)

What is Genetics?

What determines our characteristics?

ContentsContents

Summary

Self-learning Exercises

Revision & Introduction

Revision on ReproductionRevision on ReproductionTrue or False

Q1. Pollen grains are the male gametes.

TrueTrue FalseFalse


Q2. In flowering plants, ovaries will develop into seed

TrueTrue FalseFalse


Q3. Gardeners sometimes use seeds to produce new plants for flowers because this method has an advantage of preventing overcrowding as compared with vegetative propagation.

TrueTrue FalseFalse


Q4. The umbilical cord is a structure for attachment of the embryo to the uterine wall.

TrueTrue FalseFalse

Right, you are correct!!!

Pollen grains are the carries of male gametes


In flowering plants, ovaries will develop into fruits, whereas the ovules will develop into seeds.


Prevention of overcrowding is an advantage for plant dispersal only. Gardeners using seeds to produce new plants of flower, because this method can produce variations which may give rise to flowers of better quality. Such an advantage is not found in vegetation propagation.


The umbilical cord connects the embryo to the placenta instead of the uterus.

Sorry, you’re wrong!!!

Pollen grains are the carries of male gametes


In flowering plants, ovaries will develop into fruits, whereas the ovules will develop into seeds.


Prevention of overcrowding is an advantage for plant dispersal only. Gardeners using seeds to produce new plants of flower, because this method can produce variations which may give rise to flowers of better quality. Such an advantage is not found in vegetation propagation.


The umbilical cord connects the embryo to the placenta instead of the uterus.

IntroductionIntroduction Can you guess who is the son of Mr. Simpson ?

:-) Why do we resemble our parents?

Do you look like your parents?

What is genetics(What is genetics(遺傳學遺傳學 )?)?

•The study of how characteristics The study of how characteristics are passed from generation to are passed from generation to generation.generation.

What determines our characteristics?

Gene, DNA & ChromosomesGene, DNA & Chromosomes

Genes( 基因 ):basic unit of hereditypresent on chromosomeGenes are short lengths of DNA on chromosome

Genes:(Cont’d)determine the sequences of amino acidscontrols protein synthesisIndirectly controls the appearance of characters and metabolic activities of an organism

Gene, DNA & Chromosomes Gene, DNA & Chromosomes (Cont’d)(Cont’d)

DNA

(Deoxyribose nucleic acid 去氧核糖核酸 )

genetic material determining body characters by controlling types of protein produced


one from female parent

Chromosome( 染色體 ):genetic materials found inside the nucleus of the cell

made of protein & DNAeach kind of organism has a specific no. of chromosome e.g. man:46

exist in pairs in body cellthe members of each pair of chromosome is called Homologous chromosomes

one from male parent


The role of gametesThe role of gametes

As vehicles of inheritance

How gametes are formedHow gametes are formed??

by the process meiotic cell division

The major task of meiosis is to produce haploid gametes

in the process of meiosis, crossing over can occur

Meiosis(Meiosis(減數分裂減數分裂 ))Meiotic cell division including meiosis and division of cytoplasm

producing gametes which have different genetic make - up

Significance of meiosisSignificance of meiosis

Halving of chromosome no.:

The no. of chromosome can be restored at fertilization

think of what would happen if human gametes were produced by mitosis?

Independent assortment of chromosomes:

Mitosis Vs MeiosisMitosis Vs MeiosisQuestions on comparing meiotic & mitotic cell divisions:

1. Occurrence

2. Pairing of homologous chromosomes

3. Separation of homologous chromosomes

4. Number of division

5. Number of daughter cells produced from each parent cells

6. Type of daughter cells

7. Chromosome number of daughter cells

8. Function

SummarySummary

1. Gametes are formed by meiosis. (reduction division)

2. Meiotic cell division includes pairing and separation of homologous chromosomes, separation of chromatids and formation of four daughter cells

3. Meiotic cell division is significant in:

A.) forming haploid gametes, so diploid number of chromosomes can be restored at fertilization

B.) producing gametes which have different genetic make-up

Wrong Concepts

1. Meiosis is a kind of cell division.

Meiosis involves division of nucleus alone. This is only a kind of nuclear division. Cell division includes cytoplasmic and nuclear division.

2. Every characteristic is controlled by a pair of genes.

Many characteristics are controlled not by one of genes, but by many genes, e.g. height of man.

D. Fertilization

Self-Learning ExerciseSelf-Learning Exercise

Q1: What is the name for the process of fusion of male and female gametes?

A. Gametogenesis

B. Implantation

C. Pregnancy


Gametogenesis: gamete production

Try again!!!Try again!!!


Implantation: event during fertilized egg becomes embedded in uterine

wall



Pregnancy: having in the uterus offspring in a stage of development

before birth


Congratulations!!!Congratulations!!!

You’ve

got the

correct

answer!

Next

Fertilization: union of male (sperm) and female (egg) gametes

D. Mitotic cell division


Q2: How gametes are formed?

A. Meiotic cell division

B. Meiosis

C. Mitosis


Next

Gametes are formed by a process called meiotic cell division, including meiosis and division of cytoplasm


Meiosis is a kind of nuclear division.



Mitosis is a kind of nuclear division for increasing no. of cell



Mitotic cell division including mitosis and cytoplasm division


D. Proteins


Q3: Inherited characteristics are determined by?

A. DNA

B. Chromosomes

C. Genes


DNA provides the genetic information to control protein

synthesis



Chromosome carries genes



Go to End

Inherited characters are determined by genes


Proteins control body characteristics and metabolic activities


Further ReadingFurther Reading

Science Learning Network

Biological Science Page

Name: Poon Wing Ching (Prudence) Tse Man Ki (Annie) Wong Chi Yin (Stanley) By Group 3 (Part One)

Documents

flowering plants

youre wrong

new plants of flower

dna chromosomes contdgenes

dna chromosomesgenes

pollen grains

umbilical cord

male parentgene