BIOGEOSPHERE
Bilingual Biology and Geology
I.E.S. "J.S.Elcano (Sanlúcar Bda.)
1. Reproduction function
Reproduction is the joint of processes that allows living beings produce offspring. It is the ability to create new individuals, descendants, similar or identical to the progenitors.
This vital function ensures the perpetuation of the species. New individuals replace the individuals which die.
a) Types of reproduction
There are two types of reproduction:
- Asexual reproduction:
It requires only one progenitor. The descendants are identical to it.
It is carried out through specialized cells (spores) or not (parts of the body)
It is typical of bacteria, plants like ferns and some invertebrates,
among others.
- Sexual reproduction:
It requires two progenitors of different sex: male and female.
The descendants are similar but not identical to them, because they are a combination of genetic material contributed from both parents.
They produce a sexual cell called gamete (ovum and spermatozoon).
Both gametes join together to make a zygote. A new individual will grow
from that zygote.
Plants and vertebrates belong to this group.
b) Advantages and disadvantages of sexual and asexual reproduction
SEXUAL REPRODUCTION
Advantages
Genetic diversity among offspring increases the adaptation to changing environment and decreases the probability of extinction.
Disadvantages
Finding a partner and mating can be difficult and time-consuming.
Reproduction is not assured.
ASEXUAL REPRODUCTION
Advantages
Reproduction is fast, economical and efficient.
Reproduction is assured.
Disadvantages
Genetic non-diversity among offspring decreases the adaptation to a changing environment and increases the probability of extinction.
READING ACTIVITIES
After reading the text, copy and answer the following questions into your notebook:
Remember: you must make complete sentences.
1.1. Why is reproduction important for living beings?
1.2. What are the differences between sexual and asexual reproduction?
1.3. Listen and identify if the following sentences
are refered to sexual or asexual reproduction.
Now,
check
your
answers!
LISTENING ACTIVITIES
Download this worksheet
and complete it,
while you listen this audio.
(Diccionario Ing-Esp)
(Juegos de vocabulario)
(Visual dictionary)
(Visual dictionary)
(Glosario de C. Naturales)
(Science audio-glossary)
(Science audio-glossary)
(Pronunciación)
(Enciclopedia de C. Naturales)
(Tabla periódica)
Eva Mª
López Rodríguez
Departamento
Biología y Geología
IES " J. S. Elcano"
Sanlúcar de Barrameda