BIOLOGY

Unit Overview

SOI : Changes in Systems, which are balanced interactions between various processes impact humankind and environment.

Key Concept : Systems

Related Concept : Function, Interaction

Global Context : Globalization and sustainability

THE DESERT

First of all, I want to ask an important question. What is a biome?

A biome is a large area characterized by its vegetation, soil, climate, and wildlife, like a desert.

What are the noticeable features of a desert?

Deserts are very dry, because they receive very little precipitation, also have very few plants. Because deserts are so dry, they have very low humidity, which means that the sun no longer heats the desert at night and the heat from the day doesn't stay trapped. So, the day is really hot, and the night becomes very cold.

Also, watch this video on the different types of deserts.

The Science of life

BIOMES

How I am going to present my knowledge is taking a specific biome, and giving you all the information about it, in the form of the topics that we learnt this unit.

For example, I can talk about the relationships between animals in that specific biome.

Plants and Animals in the desert biome

Of course, the plants and animals vary between the different desert biomes of the world, but here are some of them -

Mammals
- Bobcat
- Coyote
- Jack lions
- Desert fox

- Camels
Birds

- Red Tailed Hawk
- Humming bird
- Turkey vulture
- Great Indian bustard (an endangered species found in the Thar desert and suffers from habitat destruction due to human activity)
Reptiles

- Rattlesnake

- Sidewinder Snake
- Desert tortoise
- Iguana
- Horned Lizard
Desert Insects

- Black widow
- Killer bees
- Fire ants
- Scorpions

Plants in the desert
- Prickly pear Cactus
- Barrel Cactus
- Saguaro Cactus

(a lot of different cactus)
- Brittlebush
- Desert Marigold

- Joshua Tree

- Desert Palm

- Tumbleweed

Adaptations to the desert biome

Plants

Cactus

thick, waxy skin to reduce loss of water and to reflect heat
large, fleshy stems to store water
thorns and thin, spiky or glossy leaves to reduce water loss
spikes protect cacti from animals wishing to use stored water
deep roots to tap groundwater
long shallow roots which spread over a wide area

Animals

Sidewinder Snake

The sideway movement of the sidewinder is specifically adapted for life in the desert
This sideways movement also allows the snake to make less contact with the ground, reducing the amount of heat absorbed
They've adapted to the temperature by learning to burrow in dens to shelter from hot temperatures.

Look at how they move below!

Trophic levels

Producers (The plants)

Primary consumers (herbivores)

Secondary consumers (omnivores or carnivores)

Tertiary consumers (carnivores)

There are usually no more than 3-4 trophic levels, because too much energy is lost, and organisms require a lot of it to survive.

A presentation of mine on the topic.

https://docs.google.com/presentation/d/1djHJHejdoL5dCqXYYgHyMzRxyct0qVxSkrkB9766g2o/edit?usp=sharing

How organisms get their energy, and the relationships of living beings

Autotrophs and heterotrophs are the 2 main types of organisms. Autotrophs are organisms that can produce their own food (like plants), whereas heterotrophs are organisms that rely on external sources of foods (animals).

Food chains and food webs.

These are also ways that organisms are connected with one another. Food chains are not a very realistic form of depicting relationships, as they are very one sided. Food webs have more complicated connections and is more realistic.

The following video is a small animation on a food chain in the desert.